The risk of acute myeloid leukemia (AML) within different occupations was studied, using occupational information obtained from the Swedish 1970 census. Follow-up in the Swedish Cancer Register was carried out from 1971 to 1984. Among male petrol station attendants, 10 cases were observed versus 2.8 expected (observed/expected = 3.6, 95% confidence interval 1.7-6.6). For several decades, Swedish petrol has contained 3-5% of benzene. Thus, a hypothesis was that benzene had contributed to the excess risk. The work histories of the 10 cases were reconstructed through interviews with surviving relatives and were compatible with the hypothesis. However, because the air benzene exposures at petrol stations always have been lower than benzene exposures associated previously with an increased risk of AML, the leukemogenic effect of benzene may have been potentiated by other petrol or vehicle exhaust components.
Comment In: Arch Environ Health. 1996 Nov-Dec;51(6):469-719012330
Exposure of the deck crew to volatile hydrocarbon compounds and polycyclic aromatic hydrocarbon PAH compounds was observed and monitored on two Norwegian product tankers. The tankers were loading their cargo with the hatches open during the monitoring period. One of the tankers loaded gas oil. This type of cargo is not volatile, and very low concentrations of the monitored chemical PAH compounds were found on this tanker. The second tanker loaded gasoline. On this tanker high concentrations of hydrocarbon compounds were found; benzene was as high as 55 ppm, toluene was as high as 34 ppm, hydrocarbon compounds in the C5-C7 range were as high as 570 ppm, n-hexane was as high as 25 ppm. The levels of PAH-compounds were low. None of the seamen working on the deck did use respiratory protective equipment during the work. The exposure of the deck crew to volatile hydrocarbon compounds ought to be reduced on product tankers. Better routines concerning the use of respiratory protective equipment is an immediate action which ought to take place. Loading volatile cargo like gasoline with the hatches open should be avoided.
Comparison of exhaust emissions from Swedish environmental classified diesel fuel (MK1) and European Program on Emissions, Fuels and Engine Technologies (EPEFE) reference fuel: a chemical and biological characterization, with viewpoints on cancer risk.
Diesel fuels, classified as environmentally friendly, have been available on the Swedish market since 1991. The Swedish diesel fuel classification is based upon the specification of selected fuel composition and physical properties to reduce potential environmental and health effects from direct human exposure to exhaust. The objective of the present investigation was to compare the most stringent, environmentally classified Swedish diesel fuel (MK1) to the reference diesel fuel used in the "European Program on Emissions, Fuels and Engine Technologies" (EPEFE) program. The study compares measurements of regulated emissions, unregulated emissions, and biological tests from a Volvo truck using these fuels. The regulated emissions from these two fuels (MK1 vs EPEFE) were CO (-2.2%), HC (12%), NOx (-11%), and particulates (-11%). The emissions of aldehydes, alkenes, and carbon dioxide were basically equivalent. The emissions of particle-associated polycyclic aromatic hydrocarbons (PAHs) and 1-nitropyrene were 88% and 98% lower than those of the EPEFE fuel, respectively. The emissions of semi-volatile PAHs and 1-nitropyrene were 77% and 80% lower than those from the EPEFE fuel, respectively. The reduction in mutagenicity of the particle extract varied from -75 to -90%, depending on the tester strain. The reduction of mutagenicity of the semi-volatile extract varied between -40 and -60%. Furthermore, the dioxin receptor binding activity was a factor of 8 times lower in the particle extracts and a factor of 4 times lower in the semi-volatile extract than that of the EPEFE fuel. In conclusion, the MK1 fuel was found to be more environmentally friendly than the EPEFE fuel.
Dangerous and cancer-causing properties of products and chemicals in the oil-refining and petrochemical industry--Part XXII: Health hazards from exposure to gasoline containing methyl tertiary butyl ether: study of New Jersey residents.
Methyl tertiary butyl ether has caused the following cancers in rats and mice: kidney, testicular, liver, lymphomas, and leukemias. Thus, in the absence of adequate data on humans, it is biologically plausible and prudent to regard methyl tertiary butyl ether-for which there is sufficient evidence of carcinogenicity in experimental animals-as a probable human carcinogen. This means that some humans are at extreme risk of contracting cancers resulting from their exposure to oxygenated gasoline containing methyl tertiary butyl ether. Immediately after the introduction of methyl tertiary butyl ether into gasoline, many consumers of this product in New Jersey, New York, Alaska, Maine, Pennsylvania, Colorado, Arizona, Montana, Massachusetts, California, and other areas, experienced a variety of neurotoxic, allergic, and respiratory illnesses. These illnesses were similar to those suffered by refinery workers from the Oil, Chemical, and Atomic Workers Union who mixed methyl tertiary butyl ether with gasoline. Additionally, these illnesses occurred following exposure to extremely low levels of methyl tertiary butyl ether in gasoline, particularly when compared to the adverse health effects that occurred only after exposure to very high levels of conventional gasoline. Thus, gasoline containing methyl tertiary butyl ether exhibited substantially more toxicity in humans than gasoline without this additive. A number of oil industry-sponsored or influenced reports alleged that these illnesses were either unrelated to exposure to reformulated gasoline or were characteristic of some yet-to-be-identified communicable disease. These studies further alleged that the widespread concern was not about illness, but was merely a reaction to the odor and the five cent increase in the price of gasoline. To clarify the significance of this issue, it is important to note that consumers have been using gasoline for many decades, with complaints only occurring following exposure to high levels at 100s ppm or higher. After the introduction of methyl tertiary butyl ether gasoline there were thousands of human health complaints. The sudden increase in widespread illnesses from which many thousands of individuals throughout the United States began to suffer immediately following the introduction of methyl tertiary butyl ether into gasoline provides strong and unquestionable evidence that gasoline containing methyl tertiary butyl ether is associated with human illnesses. When considering the severity of the illnesses in humans, it is prudent that this highly dangerous chemical be promptly removed from gasoline and comprehensive studies be conducted to assess the long-term effects that human may experience in the future from past and current exposure.
Benzene is an established cause of leukemia in adults, especially acute non-lymphocytic leukemia (ANLL). A few studies have indicated that exposure to gasoline is a cause of childhood leukemia. The purpose of this study was to investigate if environmental exposure to benzene from gasoline and car exhaust was associated with leukemia in children and young adults. The exposure to gasoline and car exhaust was estimated by the number of cars per area. In this ecology study, data on the incidence of cancer in each municipality of Sweden during an 11-year period (1975-1985) were compared with the number of cars per area. Data on the incidence of cancer for persons aged 0-24 years at diagnosis were collected from the National Swedish Cancer Register. The following diagnoses were studied: non-Hodgkin's lymphoma, acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML). We found an association between AML and car density. In municipalities with more than 20 cars/km2 the incidence of AML was 5.5 [95% confidence interval (CI) 4.4-6.8, n = 89] as compared with 3.4 (95% CI 1.9-5.7, n = 15) cases per 1 million person-years in municipalities with less than 5 cars/km2 (P = 0.05). No association was found for the other sites of cancer studied. The association between AML in young adults and car density might be attributable to exposure to benzene from gasoline vapors and exhaust gases, but further investigations are necessary before any definite conclusion can be drawn.
Methyl tertiary-butyl ether (MTBE) is widely used in gasoline as an oxygenate and octane enhancer. Acute effects, such as headache, nausea, and nasal and ocular irritation, have been associated with the exposure to gasoline containing MTBE. The aim of this study was to assess acute health effects up to the Swedish occupational exposure limit value, both with objective methods and a questionnaire. Ten healthy male volunteers were exposed to MTBE vapor for 2 h at three levels (5, 25, and 50 ppm), during light physical work (50 W). All subjects rated the degree of irritative symptoms, discomfort, and CNS effects before, during, and after all three exposure occasions using a questionnaire. Answers were given on a 100-mm visual analog scale, graded from "not at all" to "almost unbearable." Ocular (redness, tear film break-up time, self-reported tear film break-up time, conjunctival epithelial damage, and blinking frequency) and nasal (mouth and nasal peak expiratory flow, acoustic rhinometry, biochemical inflammatory markers, and cells in nasal lavage) measurements were performed mainly at the highest exposure level. The ratings of solvent smell increased dramatically (ratings up to 50% of the scale) as the volunteers entered the chamber and declined slowly with time (p
The purpose of this study was to measure the exposure of road tanker drivers at work to gasoline and some of its components. The occupational hygiene measurements were made in two depots (one in northern Finland and the other in southern Finland) and in 11 service stations of a Finnish oil company during the loading and delivery of road tankers. Of the 21 measurements made, four were taken during top submerged loading of the road tankers and six during bottom loading at the depot. Eleven measurements were made during delivery at service stations. The duration of measurements varied from 10 to 44 min. The exposure of road tanker drivers to C3-C11 hydrocarbons of gasoline was under 300 mg m-3 during bottom loading measurements and during top loading exceeded 300 mg m-3 two measurements (50%). During delivery at service stations the exposure to C3-C11 hydrocarbons of gasoline exceeded 300 mg m-3 in four measurement (36%). The exposure of road tanker drivers during delivery depended mainly on the distance between working area and the emission point of discharging vapours from the tank, vents and wind direction. The mean exposures of road tanker drivers to benzene during loading and delivery were 1.1-18 mg m-3 in various situations. The mean exposures to n-hexane, to toluene and to xylene were 0.7-6.0, 1.4-11 and 0.8-4 mg m-3, respectively. The exposures to methyl-tert-butyl ether were between 13 and 91 mg m-3. All measurements were made during the summer. However, the temperature varied between 4 and 22 degrees C.
Fine particle (PM(2.5)) emissions from traffic have been associated with premature mortality. The current work compares PM(2.5)-induced mortality in alternative public bus transportation strategies as being considered by the Helsinki Metropolitan Area Council, Finland. The current bus fleet and transportation volume is compared to four alternative hypothetical bus fleet strategies for the year 2020: (1) the current bus fleet for 2020 traffic volume, (2) modern diesel buses without particle traps, (3) diesel buses with particle traps, and (4) buses using natural gas engines. The average population PM(2.5) exposure level attributable to the bus emissions was determined for the 1996-1997 situation using PM(2.5) exposure measurements including elemental composition from the EXPOLIS-Helsinki study and similar element-based source apportionment of ambient PM(2.5) concentrations observed in the ULTRA study. Average population exposure to particles originating from the bus traffic in the year 2020 is assumed to be proportional to the bus emissions in each strategy. Associated mortality was calculated using dose-response relationships from two large cohort studies on PM(2.5) mortality from the United States. Estimated number of deaths per year (90% confidence intervals in parenthesis) associated with primary PM(2.5) emissions from buses in Helsinki Metropolitan Area in 2020 were 18 (0-55), 9 (0-27), 4 (0-14), and 3 (0-8) for the strategies 1-4, respectively. The relative differences in the associated mortalities for the alternative strategies are substantial, but the number of deaths in the lowest alternative, the gas buses, is only marginally lower than what would be achieved by diesel engines equipped with particle trap technology. The dose-response relationship and the emission factors were identified as the main sources of uncertainty in the model.